Make part of a texture transparent
Solution 1

If your image has alpha channel or you can create it¹, you can use it to mix your original shader with a transparent shader.

Your node setup adjusted:



¹Since you mentioned psd, I assume you use PhotoShop. Use the magic wand or (polygonal) lasso selector tool to: Select and delete what should be transparent; or add a mask and fill those parts of the mask with black. You may have to setup the image to enable the alpha channel.

Solution 2

If your image has black background, and is only black where the logo should be transparent, you can use that as a condition for mixing your original shader with a transparent shader.

Your node setup adjusted:



You may use other values (between 0 and 1) in the Greater than node as the threshold for masking the darkest parts of the image. Also, you may use Less then node insted to mask white areas of the image (in case your background is white).